Pressure fluid motor



June 1, 1937. E. G. GARTIN PRESSURE FLUID MOTOR Filed Nov. 1, 1934 Elmer660/4112 ,4 -,,4,

IN V EN TOR.

ATTORNEY Patented June 1, 1937 UNITED STATES PRESSURE FLUID MOTOR ElmerG. Gartin, Claremont, N. H., assignor' to Sullivan Machinery Company, acorporation of Massachusetts Application November 1, 1934., Serial No.751,009

4 Claims.

This invention relates to pressure fluid motors, and more particularlyto improvements in the control valve mechanism of such motors.

An object of this invention is to provide an improved pressure fluidmotor. Another object is to provide an improved fluid distribution meansfor such a motor having embodied therein improved and simplified fluiddistributing valve mechanism. A further object is to provide an improvedfluid distributing valve mechanism having embodied therein improvedthrottle control means. Yet another object is to provide an improvedfluid supply connection associated with the fluid distributing valvemechanism. Still another object is to provide an improved controllingmechanism for a percussive motor whereby a variable blow may beobtained. These and other objects and advantages will, however,hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustrationone form which the invention may assume in practice.

In this drawing,

Fig. l is a longitudinal sectional view through ,the illustrative formof the improved pressure fluid motor.

Fig. 2 is a View similar to Fig. 1 showing the moving motor parts in adifferent position.

Fig. 3 is a detail sectional View taken on line Of Fig. 1.

Fig. 4 is an end elevational view of the valve chest element.

Fig. 5 is an elevational view of the fluid distributing valve.

In this illustrative construction there is shown a pressure fluid motorcomprising a cylinder I having a bore 2 containing a reciprocatoryhammer piston 3. The hammer piston has a piston head 4 fitting thecylinder bore and a forwardly projecting cylindrical striking bar 5 fordeliverering impact blows to the shank of a suitable working implement6, the striking bar being guided in a bore 1 formed in the front motorhead 8. The working implement is supported within a suitable chuck 9carried by a chuck housing H]. The rear end of the cylinder bore isclosed by a rear head block II. The parts 8, l0 and II are held inassembled relation with respect to the cylinder in any suitable manner.

Now referring to the improved fluid distribution means, it will be notedthat formed in the rear head member II is a transverse bore M arrangedwith its axis extending at right angles with respect to the cylinderbore axis, and arranged in this bore is a cylindrical valve chestelement, l5 held therein by a screw plug it. Alined with the bore I4 isa reduced bore ll having arranged therein a cylindrical valve controlmember l8. Swivelly mounted in a conical bore l9 formed in the plug l6and coaxial with (Cl. l2112) the valve chest bore is a fluid supplyconnection 26, and the plug It has an inner chamber 21 for receivingfluid from the connection 20 fromher 2| in the plug I6, while the innerwall of the bore It is annularly recessed at 25. The inner face of themember if; and the inner wall of the bore M are annularly grooved at?!and 28, respectively, these grooves being arranged concentrically withinthe outer recesses 24, 26. 'The groove 28 is connected to one passage 25through a passage 29, while the recess 26 is connected to the groove 21-through a passage 30. Formed centrally within the member l5 andcommunicating with the valve chamber is a bore 3i connected through apassage 32 with a recess 33 communicating directly with the rear end ofthe cylinder bore. The valve control member is is provided with acentral bore 34 communicable through a radial port 35'with an annularrecess 38 surrounding the bore llfand this recessis connected through apassage 3? and port 38 with the forward end of the cylinder bore. Thecyltra-lly located free exhaust port 39.

When the parts are in the position shown Fig. 1, pressure fluid may flowthrough the swivel connection 28, groove 2|, passages 25, recesses 24,through the valve chamber past the outer face of the valve 23, 'bore 3i,passage 32 and chamber 33 to the rear end of the cylinder bore, thepressure fluid acting on the'rear pressure area of the'motor piston todrive the latter forwardly to effectits working stroke, i. e.,'todeliver an impact blow to the shank of the working implement 5. wardly,the piston head l closes the central exhaust port-39, and upon continuedforward movementof the piston, the rear edge of the piston head overrunsthe exhaust port 39, thereby con- I nesting the rear end of the cylinderbore to ex- I haust, and as a result, there is a material reduction inpressure in the valve chamber at the outer side of the valve. Theconstant pressure in groove 2? acting on the inner face ofthevalvetogether with the compression pressure built up in cham As themotor piston moves forside of the valve, through the bore 34 in thevalve I8, and through port 35, recess 36, passage 31 and port 38 to theforward end of the cylinder bore, the pressure fluid acting on theforward pressure area of the piston to drive the latter rearwardly. Asthe motor piston moves rearwardly the piston head closes the exhaustport 39, and upon continued rearward movement of the motor piston, theforward edge of. the piston head overruns the free exhaust port 39,thereby connecting the front end of the cylinder bore to exhaust; and asa result there is a material reduction in pressure in passage 31, bore34 and in the valve chamber at the inner side of the valve. The constantpressure in groove 28 acting on the outer face of the valve, plus thecompression pressure in chamber 3 I, overcomes the opposing reducedpressure and throws the valve inwardly from the position shown in Fig. 2to the position shown in Fig. 1. These operations are rapidly repeatedduring normal operation of the motor. 7

Associated with the fluid distributing valve is the improved throttlecontrol means comprising the valve control member l8. The member 18 isthreaded at 43 within the head member ll and is provided with anoperating handle 44. When it is desired to throttle the motor, theoperator grasps the handle 44 and rotates the member l8, thereby movingthe latter axially inwardly so that the inner end thereof engages theinner face of the valve 23, moving the valve tightly against itsouterseat in the position shown in Fig. 2, the inner end of the memberl8 at the same time having tight end surface contact with the innersurface of the valve. As a result, the distributing valve is held in theposition in Fig. 2 while the inner end of the member l8 tightly engagesthe inner face of the distributing valve. The parts when in thisposition close oiT communication of the fluid supply passage 25 with thebores 3| and 34, thereby cutting oil supply of pressure fluid to themotor. When the memwill be provided continued operation ofxthe motor,

but with reduced force of blow, and a tendency toward shortstroking. Itis true that there will be an increased constant pressure'difierential,so

to speak, at the left hand end of the valve, but

this will not be adequate to preclude the normal automatic operation ofthe valve, although it will vary the instant of movement of the valvefrom left to right position, as from that in Fig.

l to that in Fig. 2. Accordinglysince this increased differential areawill speed up the throw of the valve with respect to the forward strokeof the piston, a very beneficial result. is obtained by my invention inthe blow lightening function which can be obtaine'd'in the manner'described.

.As a result of this invention, it will be noted that an improved fluiddistribution means is provided which is of an extremely simple design,the

improved fluid distribution means having associated therewith animproved fluid supply connection so that a substantially direct fluidsupply to the valve chamber is attained. It will further be noted thatby associating the throttle valve control element with the distributingvalve the throttle controlling function of the motor is greatlysimplified. Moreover it will be observed that a very simple andeffectivemeans for varying the blow and the piston travel is provided.These and other uses and advantages of the improved pressure fluid motorwill be clearly apparent to those skilled in the art.

While there is in this applicatian specifically described one form whichthe invention may assume in practice, it will be understood that thisform of the same is shown for purposes of illustration and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a pressure fluid motor, a cylinder having a piston reciprocabletherein, and fluid distribution means for effecting reciprocation ofsaid piston including a fluid actuated distributing valve, means forsubjecting an area on said valve to a throwing pressure, and means forchanging said efiective area on which the throwing pressure acts toalterthe time of valve throw.

2. In a pressure fluid motor, a cylinder having a bore, a pistonreciprocable therein, fluid distribution means for effectingreciprocation of said piston including an automatic fluid actuated fluiddistributing valve, throttle means associated with said valve andengageable with the latter to move said valve into a position to closecompletely the supply of pressure fluid past said valve to said cylinderbore, and abutment means relative to which said throttle means isadjustable for limiting movement of the valve'in opposite directionsduring the normal fluid distributing function of the valve and when saidthrottle means is moved out of the path of normal valve travel.

3. In a pressure fluid motor, a cylinder having a hammerpistonreciprocable therein, and fluid distribution means for effectingreciprocation of 'said piston including a fluid actuated fluiddistributing valve, stop means for limiting movement of said'valve inopposite directions during its normal operation, and adjustable controlmeans associated with said valveand movable relative to said .stopmeans, said control means engageable with said valve at one side thereoftributing valve, stop means for limiting movement of said valve duringits normal operation, and adjustable control means associated with saidvalve and movable relative to said stop means, said control meansengageable with said valve at one sidethereof to effect varied ranges ofmovement of said valve to control the force of the piston blow, one ofsaid stop means having a central bore'and said control means beingmovable in said central bore.

ELMER G. GARTIN.

